Washington — The Pentagon on Monday asked media organizations not to publish any classified war files released by the WikiLeaks Web site, as the U.S. braces for the potential disclosure of hundreds of thousands of secret Iraq war documents.In July, WikiLeaks obtained and released nearly 77,000 classified military reports from Afghanistan. Now, the Pentagon says the group has as many as 400,000 documents from a military database on operations in Iraq.WikiLeaks editor-in-chief Julian Assange on Monday downplayed expectations that a leak was imminent. In a Twitter post, Assange said information were coming from "a single tabloid blog" that had put out a "tremendous amount" of false information about his site.Still, the military says its 120-person task force has been on high alert. The group has been reviewing the documents for weeks to determine what information might be compromised.Marine Corps Col. Dave Lapan, a Pentagon spokesman, told reporters that the military isn't sure if WikiLeaks has shared the Iraq war logs with any news organizations. But, he said, media should not disseminate the "stolen" information even if it's already posted online by WikiLeaks."The concern is that WikiLeaks as an organization should not be made more credible by having credible news organizations facilitate what they're doing," Lapan said.WikiLeaks was largely unknown until this spring, when it released a gritty war video of Army helicopters gunning down a group of men — including two unarmed Reuters photographers — in Iraq.The group in July gained international notoriety when it coordinated its release of the 77,000 Afghan war logs with The New York Times, The Guardian in London and the German magazine Der Spiegel.The New York Times says it omitted information from its coverage that would have jeopardized military operations or exposed Afghan informants. The Times also declined to provide a Web link to the WikiLeaks data base.Der Spiegel and The Guardian said it withheld sensitive information as well, although The Guardian published a selection of the documents that it believed were significant.Secretary of Defense Robert Gates has told Congress that the July leak did not expose the nation's most sensitive intelligence secrets. But, he maintained, the release still put U.S. interests at risk because it exposed the names of some Afghans who had cooperated with U.S. forces.The military has an ongoing investigation into how the documents were leaked. An Army intelligence analyst stationed in Iraq, Spc. Bradley Manning, has been arrested in connection with the release of other materials to WikiLeaks.In a separate development Monday, Swedish authorities have rejected Assange's request for residency, a potential setback in his efforts to gain protection from Swedish press freedom laws.Associated Press Writer Malin Rising in Stockholm contributed to this report.